Connectionless food steamer with automatic electric steam trap

Abstract

A connectionless steam cooker has an insulated housing that surrounds an internal cooking compartment accessible through a door. A supply of water is held in the compartment and immerses a plate-like heating element mounted at the floor, preferably of the electrical resistance type. A steam outlet located above the maximum water level is in fluid communication with and adjacent an electrically-operated solenoid valve that is normally open to atmosphere. A temperature sensor in close physical proximity to the steam outlet and the solenoid valve closes the solenoid wherein the sensed steam temperature is at or above a set level. The outlet steam is also connected to a pair of water column pressure-responsive microswitches. One microswitch controls power to the heating element. It is set closely, e.g. to cycle between ON and OFF in response to a sensed pressure range of 1 and 3 inches of water W.C.) The second microswitch responds to a higher set pressure (e.g. 9 inches W.C.) indicative of an unsafe over-pressure to open the solenoid valve to vent the steam to atmosphere. The heating element is mounted with a tilt with respect to the horizontal water level. Two heat-sensing elements are secured on upper and lower portions of the tilted heater plate, preferably diagonally opposite corners. The temperature sensors are each set to produce an output alarm signal when the adjacent region of the heating element is not immersed in water.